Display device and method of fabricating the same

ABSTRACT

A display device includes a display area, a test pad, a plurality of first test transistors, and at least one outline. The display area includes pixels coupled to data lines and scan lines. The test pad receives a test signal. The first test transistors are coupled between the data lines of the display area and the test pad. The at least one outline is coupled between one of the first test transistors and the test pad. The at least one outline is located in a non-display area outside the display area.

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2014-0101136, filed on Aug. 6, 2014,and entitled: “Display Device and Method of Fabricating the Same,” isincorporated by reference herein in its entirety.

BACKGROUND

1. Field

One or more embodiments described herein relate to a display device anda method for fabricating a display device.

2. Description of the Related Art

Liquid crystal displays, organic light emitting diode displays,electrophoretic displays, and other types of flat panel displays havebeen developed. These displays have panels with pixels coupled to datalines and scan lines. In operation, driving circuits supply scan signalsto the scan lines and data signals to the data lines. The data lines,scan lines, and pixels may be provided on array substrates of thedisplay panels.

When a display panel is hit by debris during manufacturing, cracks mayform at various areas including the array substrates. As a result, thedata and/or scan lines may be disconnected, or a resistance of the dataand/or scan lines may increase. The pixels therefore may emit lightinaccurately or not at all.

Recently, flexible displays have been developed. When displays of thistype have minute cracks, the cracks may become larger as the displaysare bent or become crooked. Often, these minute cracks are not detectedbefore the displays are released to the public. As a result, the pixelsmay not emit light or may emit light inaccurately.

SUMMARY

In accordance with one embodiment, a display device includes a displayarea including pixels coupled to data lines and scan lines; a test padto receive a test signal; a plurality of first test transistors coupledbetween the data lines of the display area and the test pad; and atleast one outline coupled between one of the first test transistors andthe test pad, the at least one outline in a non-display area outside thedisplay area. The at least one outline may traverse a path adjacent thedisplay area once.

The first test transistor may be coupled to the at least one outline,the at least one outline may be coupled to a data line, and the dataline may be coupled to at least one green pixel or sub-pixel in thedisplay area. The display device may include a resistance between one ofthe first test transistors that is not coupled to the at least oneoutline and the test pad. The resistance may be a resistor.

The display device may include a test control pad coupled to controlelectrodes of the first test transistors; a plurality of initializationtransistors coupled between the data lines of the display area and padsto receive initialization signals; and a plurality of initializationcontrol pads coupled to control electrodes of the initializationtransistors. The display device may include a plurality of data padscoupled to the data lines. The test pad, the test control pad, theinitialization control pads, the data pads, the test transistors, theinitialization transistors, and the at least one outline may be in thenon-display area.

The test control pad may receive a test control signal that is oppositeto an initialization control signal received by one of theinitialization control pads. The scan signals may be coupled to the scanlines within a period during which the test control signal is suppliedas first gate-on voltage value, and the scan signals may be supplied assecond gate-on voltages value.

The display device may include a plurality of first test control padscoupled to control electrodes of the first test transistors; a pluralityof initialization transistors coupled between the data lines in thedisplay area and initialization pads to receive initialization signals;a plurality of initialization control pads coupled to control electrodesof the initialization transistors; a second test transistor coupledbetween one of the data lines and the at least one outline; a secondtest control pad coupled to a control electrode of the second testtransistor; and a plurality of data pads coupled to the data lines.

The first and second test control pads may receive a test control signalopposite to an initialization control signal received by one of theinitialization control pads. The scan signals coupled to the scan linesmay be supplied as second gate-on voltage value, during a period whenthe test control signal is supplied as a first gate-on voltage value.The test pad, the first and second test control pads, the initializationcontrol pads, the data pads, the first and second test transistors, theinitialization transistors, and the at least one outline may be in thenon-display area.

In accordance with another embodiment, a method for manufacturing adisplay device includes manufacturing an array substrate of a displaypanel; and inspecting the array substrate of the display panel for acrack.

The manufacturing operation may include forming data lines on the arraysubstrate of the display panel, scan lines crossing the data lines, aplurality of pixels coupled to the data lines and the scan lines, a testpad, a plurality of first test transistors coupled between the datalines of the display area and the test pad, at least one outline coupledbetween one of the first test transistors and the test pad, the at leastone outline in a non-display area, a control pad coupled to controlelectrodes of the first test transistors, a plurality of initializationtransistors coupled between the data lines of a display area and pads toreceives initialization signals, and a plurality of initializationcontrol pads coupled to control electrodes of the initializationtransistors.

The inspecting operation may include supplying a test signal to the testpad, supplying a test control signal to the test control pad, andsupplying initialization control signals to the initialization controlpads, wherein the test control signal is opposite to one of theinitialization control signals.

The manufacturing may include forming a plurality of data lines on thearray substrate of the display panel, a plurality of scan lines crossingthe data lines, a plurality of pixels coupled to the data lines and thescan lines, a test pad, a plurality of first test transistors coupledbetween the data lines of the display area and the test pad, at leastone outline coupled between one of the first test transistors and thetest pad, the at least one outline in a non-display area, a plurality offirst test control pads coupled to control electrodes of the first testtransistors, a plurality of initialization transistors coupled betweenthe data lines of a display area and the pads to receive initializationsignals, a plurality of initialization control pads coupled to controlelectrodes of the initialization transistors, a second test transistorcoupled between the initialization transistor and the at least oneoutline; and a second test control pad coupled to a control electrode ofthe second test transistor.

The inspecting operation may include supplying a test signal to the testcontrol pad, supplying a test control signal to the first and secondtest control pads; an supplying initialization control signals to theinitialization control pads, wherein the test control signal is oppositeto one of the initialization control signals.

The method may include performing a module process; and re-inspectingcracks on the display panel after the module process, wherein theperforming includes attaching the array substrate to an oppositesubstrate of the display panel; attaching a flexible film to the arraysubstrate; attaching the flexible film to the source printed circuitboard; and coupling a control printed circuit board and the sourceprinted circuit board using a flexible cable.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail exemplary embodiments with reference to the attached drawingsin which:

FIG. 1 illustrates an embodiment of a display device;

FIG. 2 illustrates an embodiment of a pixel;

FIG. 3 illustrates an embodiment of an array substrate of a displaypanel;

FIG. 4 illustrates an example of signals for the display panel;

FIGS. 5A-5C illustrate examples of a signals for controlling the pixel;

FIG. 6 illustrates an embodiment of a coupling structure between a testtransistor and an outline and the test transistor and the resistance inFIG. 3;

FIG. 7A illustrates a view taken along section line I-I′ in FIG. 6, andFIG. 7B illustrates a view taken along section line II-II′ in FIG. 6;

FIG. 8 illustrates another embodiment of an array substrate of a displaypanel;

FIG. 9 illustrates another embodiment of an array substrate of a displaypanel;

FIG. 10 illustrates an embodiment of a lower side of a display panel;

FIG. 11 illustrates an embodiment of a method for manufacturing adisplay; and

FIG. 12 illustrates another embodiment of a method for manufacturing adisplay.

DETAILED DESCRIPTION

Example embodiments are described more fully hereinafter with referenceto the accompanying drawings; however, they may be embodied in differentforms and should not be construed as limited to the embodiments setforth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully conveyexemplary implementations to those skilled in the art.

In the drawing, the dimensions of layers and regions may be exaggeratedfor clarity of illustration. It will also be understood that when alayer or element is referred to as being “on” another layer orsubstrate, it can be directly on the other layer or substrate, orintervening layers may also be present. Further, it will be understoodthat when a layer is referred to as being “under” another layer, it canbe directly under, and one or more intervening layers may also bepresent. In addition, it will also be understood that when a layer isreferred to as being “between” two layers, it can be the only layerbetween the two layers, or one or more intervening layers may also bepresent. Like reference numerals refer to like elements throughout.

FIG. 1 illustrates an embodiment of a display device which includes adisplay panel 10, a scan driver 20, a data driver, and a timingcontroller (TC) 40. The display device may be an organic light emittingdisplay OLED, or another type of display including but not limited to aliquid crystal display, a field emission display, or a plasma displaypanel.

Data lines D1 to Dm (m≧2) and scan lines S1 to Sn (n≧2) cross each otherat the display panel 10. Pixels P arranged in a matrix are located atcrossing regions of the data lines D1 to Dm and the scan lines S1 to Sn.The pixels P are in a display area DA of the display panel 10. Thepixels P may be pixels or sub-pixels. In the latter case, the sub-pixelsmay emit light of different colors.

Each of the pixels P are coupled to one scan line and one data line.Each of the pixels P receives a data signal through a corresponding oneof the data lines when a san signal is supplied to a respective scanline. Each of the pixels P emit light with a predetermined brightness bycontrolling current flowing to an organic light emitting diode. Themagnitude of the current is based on a voltage value of a supplied datasignal.

The scan driver 20 receives a scan timing control signal from the timingcontroller 40. The scan driver 20 generates scan signals depending on ascan timing control signal SCS. The scan driver 20 supplies scan signalsto the scan lines S1 to Sn.

The scan driver 20 is located adjacent one or more sides of the displayarea DA. The scan driver 20 may be formed concurrently with the datalines D1 to Dm, the scan lines S1 to Sn, and the pixels P using, forexample, an amorphous silicon TFT gate driver ASG method or a gatedriver in panel GIP method. Alternatively, the scan driver 20 may bemounted on a tape carrier package or a flexible film. The tape carrierpackage or flexible film on which the scan driver 20 is mounted may beattached to an array substrate of the display panel 10 by a tapeautomated bonding TAB process. The scan driver 20 may be coupled to gatepads, which are coupled to the scan lines S1 to Sn.

The data driver includes at least one source drive IC 30. The sourcedrive IC 30 receives digital video data signal and a source timingcontrol signal from the timing controller 40. The source drive IC 30converts digital video data signal into data signals by responding tothe source timing control signal. The source drive IC 30 supplies thedata signals to the data lines D1 to Dm by being synchronized to each ofthe scan signals. As a result, the data signals are supplied to thepixels P to which the scan signals are supplied.

The source drive IC 30 may be mounted on the flexible film FF and may beattached to the array substrate of the display panel 10 and a sourceprinted circuit board SP. The source drive IC 30 may be coupled to datapads coupled to the data lines D1 to Dm. Alternatively, the source driveIC 20 may be attached to the array substrate of the display panel 10 andcoupled to the data pads using a chip-on-glass process or achip-on-plastic glass.

The timing controller 40 receives the digital video data and the timingsignals. The timing signals may include vertical sync signals,horizontal sync signals, data enable signals, dot clock, and/or othersignals. The timing controller 40 generates timing control signals forcontrolling operation timing of the data driver and the scan driver 30based on the timing signals. The timing control signals may include scantiming control signals for controlling operation timing of the scandriver 20 and data timing control signals for controlling operationtiming of the data driver. The timing controller 40 outputs the scantiming control signals to the scan driver 20 and outputs data timingcontrol signals and digital video data to the data driver.

The timing controller 40 may be mounted on a control printed circuitboard CP. The control printed circuit board CP and the source printedcircuit board SP may be coupled to each other through a flexible cableFC, such as a flexible flat cable FFC or a flexible printed circuit FPC.

A power supply source may supply not only driving signals to the scandriver 20, the data driver 30, and the timing controller 40, but also afirst power signal through a first power voltage line and a second powersignal through a second power voltage line. The first power signal maybe supplied to the pixels P through the first power voltage line coupledto the pixels P. The second power signal may be supplied to the pixels Pthrough the second power voltage line coupled to cathode electrodes ofthe organic light emitting diodes of the pixels P. A voltage value ofthe first power signal may be set to a predetermined (e.g., high)voltage value and a voltage value of the second power signal may be setto a predetermined (e.g., low) voltage value.

FIG. 2 illustrates an example of a pixel, which, for example, may be anyof the pixels P in FIG. 1. Referring to FIG. 2, the pixels P may becoupled to a k-th (1≦k≦n) scan line Sk, a j-th (1≦j≦m) data line Dj, afirst power voltage line VDDL, and a second power voltage line VSSL. Thepixels P may also include a driving transistor DT, an organic lightemitting diode OLED, a scan transistor ST, and a capacitor C.

The driving transistor DT is between the organic light emitting diodeOLED and the first power voltage line VDDL, and controls an amount of acurrent flowing to the organic light emitting diode OLED. Since anamount of a current flowing in a channel of the driving transistor DTmay change depending on the voltage value of the data signal supplied toa control electrode of the driving transistor DT, the amount of thecurrent flowing to the organic light emitting diode OLED may becontrolled as the voltage value of the data signal supplied to a gateelectrode of the driving transistor DT is controlled.

The control electrode of the driving transistor DT is coupled to asecond electrode of the scan transistor ST, the first electrode iscoupled to the first power voltage line VDDL, and the second electrodeis coupled to an anode electrode of the organic light emitting diodeOLED. In one embodiment, the control electrode is a gate electrode, thefirst electrode is a source electrode or a drain electrode, and thesecond electrode is an electrode different from the first electrode. Forexample, when the first electrode is a source electrode, the secondelectrode is a drain electrode, or vice versa.

The organic light emitting diode OLED may emit light depending on thecurrent between the drain and the source of the driving transistor DT.The organic light emitting diode OLED has a anode electrode coupled tothe second electrode of the driving transistor DT and a cathodeelectrode coupled to the second power voltage line VSSL.

The scan transistor ST is coupled between the gate electrode of thedriving transistor DT and the j-th data line Dj. The scan transistor STis turned on by a scan signal of the k-th scan line SLk and supplies adata signal of the j-th data line Dj to the gate electrode of thedriving transistor DT. The gate electrode of the scan transistor ST iscoupled to a k-th scan line SLk, the first electrode is coupled to thej-th data line Dj, and the second electrode is coupled to the gateelectrode of the driving transistor DT.

The capacitor C is between the gate electrode of the driving transistorDT and the first power voltage line VDDL. The capacitor C maintains thedata signal supplied to the gate electrode of the driving transistor DTfor an amount of time.

Each of semiconductor layers of the driving transistor DT and the scantransistor ST may include polysilicon, a-Si, an oxide semiconductor, oranother material. In FIG. 3, the driving transistor DT and the scantransistor ST are P-type transistors. In another embodiment, n-typetransistors may be used.

The pixels P may include a compensating circuit to compensate athreshold voltage value of the driving transistor DT. The compensatingcircuit may include at least one transistor, and may sense the thresholdvoltage value of the driving transistor DT and reflect it to the gateelectrode. Therefore, a current Ids between the drain and the source ofthe driving transistor DT may not depend on the threshold voltage valueVth of the driving transistor DT. The pixels in FIG. 1 may have astructure different from the one in FIG. 2 in other embodiments.

FIG. 3 illustrates an embodiment of an array substrate of a displaypanel, which, for example, may be the display panel 10 in FIG. 1.Referring to FIG. 3, the display panel 10 includes an array substrate LSand an opposite substrate. The array substrate LS includes the displayarea DA and a non-display area NDA. The display area DA displaysincludes pixels RP, GP, and BP for generating light of an image. Thenon-display area NDA is outside the display area DA.

The pixels RP, GP and BP in the display area DA of the array substrateLS may be arranged in a matrix at crossing regions of the data lines D1to Dm and the scan lines S1 to Sn. Each of the pixels RP, GP and BP iscoupled to one scan line and one data line. Although red and blue pixelsRP and BP are illustrated in FIG. 3 as being coupled to odd data linesand green pixels GP are illustrated as being coupled to even data lines,the coupling arrangement of the pixels P may be different in otherembodiments.

Data pads DP1 to DPo (o>m), initialization control pads IP1, IP2 andIP3, a first test control pad TP1, test pads TVP1 and TVP2,initialization transistors IT1, IT2 and IT3, first test transistors TT1,resistance R, and outlines OL1 and OL2 are in the non-display area NDAof the array substrate LS. When the scan driver 20 is formed using theASG method or the GIP method, the scan driver 20 may be in thenon-display area NDA adjacent one side of the display area DA.

The data pads DP1 to DPo are coupled to the data lines D1 to Dm throughthe initialization transistors IT1, IT2 and IT3. In order to inspectcracks of the array substrate LS, initialization signals may be suppliedto the data pads DP1 to DPo. The source drive IC 30 may be attached to acompleted display panel 10 as shown in FIG. 1. Here, the data pads DP1to DPo may be attached to the source drive IC 30, e.g., data signals maybe supplied to the data lines D1 to Dm of the completed display panel 10as the data signals are supplied to the data pads DP1 to DPo.

The initialization control pads IP1, IP2 and IP3 may include three (3)initialization control pads as shown in FIG. 3. The initializationtransistors IT1, IT2 and IT3 may include three (3) initializationtransistors. The first initialization control pad IP1 may be coupled tocontrol electrodes of the first initialization transistors IT1. Thesecond initialization control pad IP2 may be coupled to controlelectrodes of the second initialization transistors IT2. The thirdinitialization control pad IP3 may be coupled to control electrodes ofthe third initialization transistors IT3. The first initializationcontrol signal may be supplied to the first initialization control padIP1. The second initialization control signal may be supplied to thesecond initialization control pad IP2. The third initialization controlsignal may be supplied to the third initialization control pad IP3.

The first test control pad TP1 may be coupled to each control electrodeof the first test transistors TT1. The test control signal may besupplied to the first test control pad TP1.

The test pads TVP1 and TVP2 may be coupled to the first electrodes ofthe first test transistors TT1. The test signal(s) may be supplied tothe test pads TVP1 and TVP2. A same voltage value of the test signal, ordifferent voltage value of the test signals, may be supplied to thefirst and second test pads TVP1 and TVP2. For example, a same voltagevalue of the test signal may be supplied to the first and second testpads TVP1 and TVP2. Also, the first test signal may be supplied to thefirst test pad TVP1, and the second test signal may be supplied to thesecond test pad TVP2.

The initialization transistors IT1, IT2 and IT3 may be coupled betweenthe data lines D1 to Dm and the data pads DP1 to DPo. The controlelectrodes of the first initialization transistors IT1 may be coupled tothe first initialization control pad IP1. The control electrodes of thesecond initialization transistors IT2 may be coupled to the secondinitialization control pad IP2. The control electrodes of the thirdinitialization transistors IT3 may be coupled to the thirdinitialization control pad IP3.

Each control electrode of the first initialization transistors IT1 maybe coupled to the first initialization control pad IP1. The firstelectrode may be coupled to any one of the data lines D1 to Dm. Thesecond electrode may be coupled to any one of the data pads DP1 to DPo.Each control electrode of the second initialization transistors IT2 maybe coupled to the second initialization control pad IP2. The firstelectrode may be coupled to any one of the data lines D1 to Dm. Thesecond electrode may be coupled to any one of the data pads DP1 to DPo.Each control electrode of the third initialization transistors IT3 maybe coupled to the third initialization control pad IP3. The firstelectrode may be coupled to any one of the data lines D1 to Dm. Thesecond electrode may be coupled to any one of the data pads DP1 to DPo.

The first and second initialization transistors IT1 and IT2 coupled toadjacent data pads may be coupled to one data line. The thirdinitialization transistor IT3 adjacent to the first and secondinitialization transistors IT1 and IT2 may be coupled to a differentdata line. For example, the first initialization transistor IT1 coupledto the first data pad DP1 and the second initialization transistor IT2coupled to the second data pad DP2 may be coupled to the first data lineD1. The third initialization transistor IT3 coupled to the third datapad DP3 may be coupled to the second data line D2.

The first test transistors TT1 may be coupled between the data lines D1to Dm and the test pads TVP1 and TVP2. The control electrodes of thefirst test transistors TT1 may be coupled to the first test control padTP1. For example, each control electrode of the first test transistorsTT1 may be coupled to the first test control pad TP1. The firstelectrode may be coupled to any one of the test pads TVP1 and TVP2. Thesecond electrode may be coupled to any one of the data lines D1 to Dm.

The outline may be between the first electrode of the first testtransistor TT1 and the test pad. For example, as shown in FIG. 3, afirst outline OL1 may be between the first electrode of the first testtransistor TT1 coupled to the first data line D1 and the first test padTVP1. A second outline OL2 may be between the first electrode of thefirst test transistor TT1 coupled to a m-th data line Dm and the secondtest pad TVP2. That is, the first outline OL1 may be coupled between thefirst electrode of the first test transistor TT1 coupled to the firstdata line D1 and the first test pad TVP1. The second outline OL2 may becoupled between the first electrode of the first test transistor TT1coupled to the m-th data line Dm and the second test pad TVP2.

Each of the outlines OL1 and OL2 may be outside the display area DA. Forexample, the first outline OL1 may be adjacent a left side of thedisplay area DA, and the second outline OL2 may adjacent a right side ofthe display area DA. Also, when the scan driver 20 is in the non-displayarea DA adjacent one side of the display area DA, the outlines OL1 andOL2 may be further outside than the scan driver 20. Also, the outlinesOl1 and OL2 may be on the outermost side, among the structures formed atthe array substrate LS, to surround the structures formed at the arraysubstrate LS. Here, the structures at the array substrate LS may referto any structure other than the pads.

Particularly, each of the outlines OL1 and OL2 may be adjacent and go atleast partially around the outside of the display area DA once. Forexample, the first outline OL1 may be adjacent and go at least partiallyaround the outside on the left side of the display area DA once, and thesecond outline OL2 may be adjacent go at least partially around theoutside of the right side of the display area DA once.

A voltage value difference between the test signal supplied to the firsttest transistors TT1 (via the outlines OL1 and OL2 from the test padsTVP1 and TVP2) and the test signal supplied to the first testtransistors TT1 (without passing through the outlines OL1 and OL2 fromthe test pads TVP1 and TVP2) may occur due to wire resistance on theoutlines OL1 and OL2.

To prevent the voltage value difference, resistances R may be locatedbetween the first electrodes of the first test transistors TT1 notcoupled to the outlines OL1 and OL2 and the test pads TVP1 and TVP2. Asa result, the voltage value difference in test signal due to wireresistance of the outlines may be reduced or minimized. For example, aresistance value of the first outline OL1, a resistance value of thesecond outline OL2, and a resistance value of the resistance R may beset in substantially the same in order to reduce the voltage valuedifference in test signal due to each wire resistance of the outlinesOL1 and OL2.

In the array substrate LS in the embodiment of FIG. 3, the first testtransistors TT1 and the resistances R are illustrated in an uppernon-display area NDA. The data pads DP1 to DPo, the initializationcontrol pads IP1, IP2 and IP3, the first test control pad TP1, the testpads TVP1 and TVP2, and the initialization transistors IT1, IT2 and IT3are in a lower non-display area NDA. However, the arrangement of thedata pads DP1 to DPo, the initialization control pads IP1, IP2 and IP3,the first test control pad TP1, and the test pads TVP1 and TVP2 may bedifferent in other embodiments.

FIG. 4 illustrates examples of signals for controlling the display panelin FIG. 3. Initialization control signals IS1, IS2 and IS3 supplied toinitialization control pads IP1, IP2, and IP3, test control signal TSsupplied to the first test control pad TP1, initialization signal IVsupplied to data pad DP1 to DPo, the test signal TV supplied to the testpads TVP1 and TVP2, and first to third and n-th scan signals SCAN1,SCAN2, SCAN3, and SCANn are shown in FIG. 4.

Referring to FIG. 4, a first frame period includes a plurality ofhorizontal periods, a first horizontal period including the first periodT1 and the second period t2. The first frame period is a period whendata signals are supplied to all pixels of the display panel 10. Thefirst horizontal period is a period when data signals are supplied topixels coupled to one scan line.

The first initialization control signal IS1 has a first gate on voltagevalue Von1 during the first period t1 of the horizontal period oh, andhas a first gate off voltage value Voff1 during the second period t2 ofthe odd horizontal periods oh and the even horizontal periods eh. Thesecond initialization control signal IS2 has the first gate on voltagevalue Von1 during the first period t1 of the even horizontal period eh,and has the first gate off voltage value Voff1 during the odd horizontalperiod oh and the second period t2 of the even horizontal period eh. Thethird initialization control signal IS3 has the first gate on voltagevalue Von1 during the first period t1 of each horizontal period, and hasthe first gate off voltage value Voff1 during the second period t2.

The test control signal TS has the first gate off voltage value Voff1during the first period t1 of each horizontal period, and has the firstgate on voltage value Von1 during the second period t2. When theinitialization transistors IT1, IT2, and IT3 and the first testtransistor TT1 are P-type transistors as shown in FIG. 3, the first gateon voltage value Von1 is lower than the first gate off voltage valueVoff1. For example, as shown in FIG. 4, the test control signal TS isopposite to the third initialization control signal IS3.

The initialization signal IV may be set to a peak white gray levelvoltage value PWV, and the test signal TV may be set to a peak blackgray level voltage value PBV. When the driving transistor DT is a P-typetransistor as shown in FIG. 2, the peak white gray level voltage valuePWV may be lower than the peak black gray level voltage value PBV asshown in FIG. 4. In FIG. 4, an example of the initialization signal IVand the test signal TV are shown. The initialization signal IV and thetest signal TV may have different voltage value in other embodiments.

The first to third and n-th scan signals SCAN1, SCAN2, SCAN3, and SCANnhave the second gate off voltage value Voff2 during the first period t1of each horizontal period, and have the second gate on voltage valueVon2 during the second period t2. In FIG. 4, an example is shown wherefirst to third and n-th scan signals SCAN1, SCAN2, SCAN3, and SCANn havethe second gate on voltage value Von2 during a period shorter than thesecond period t2 within the second period t2 of each horizontal period,but the present invention is not limited thereto. For example, the firstto third and n-th scan signals SCAN1, SCAN2, SCAN3, and SCANn may havethe second gate on voltage value Von2 during the second period t2 ofeach horizontal period. When the scan transistor ST is a P-typetransistor as shown in FIG. 2, the second gate on voltage value Von2 maybe lower than the second gate off voltage value Voff2 as shown in FIG.4.

When the scan transistors ST of the pixels RP, GP, and BP have the sametransistor characteristics as the first to third initializationtransistors IT1, IT2, and IT3 and the first test transistors TT1, thesecond gate on voltage value Von2 may have substantially same as thefirst gate on voltage value Von1, and the second gate off voltage valueVoff2 may have substantially same as the first gate off voltage valueVoff1.

FIGS. 3 and 4 illustrate operations in an embodiment of a method forinspecting a display panel for cracks. The first initialization controlsignal IS1 and the third initialization control signal IS3 have thefirst gate on voltage value Von1 during the first period t1 of the oddhorizontal periods oh. The second initialization control signal IS2 andthe test control signal TS have the first gate off voltage value Voff1.Therefore, the first initialization transistors IT1 and the thirdinitialization transistors IT3 are turned on, and the secondinitialization transistors IT2 and the first test transistors TT1 areturned off. Thus, the initialization signal IV may be supplied to thefirst to m-th data lines D1 to Dm through the first and thirdinitialization transistors IT1 and IT3.

The first to third initialization control signals IS1, IS2 and IS3 havethe first gate off voltage value Voff1 and the test control signal TShave the first gate on voltage value Von1 during the second period t2 ofodd horizontal period oh. Therefore, the first to third initializationtransistors IT1, IT2, and IT3 are turned off and the first testtransistors TT1 are turned on. Accordingly, the test signal TV may besupplied to the first to m-th data lines D1 to Dm through the first testtransistors TT1.

Also, when the first scan signal SCANT has the second gate on voltagevalue Von2 within the second period t2 of the odd horizontal period oh,signals of the first to m-th data lines D1 to Dm are supplied to the redand green pixels RP and GP coupled to the first scan line S1.

When a voltage value of the initialization signal IV is the peak whitegray level voltage value PWV and a voltage value of the test signal TVis the peak black gray level voltage value PBV, the voltage value to besupplied to the pixels may decrease to the peak white gray level voltagevalue PWV during the first period t1 and increase to the peak black graylevel voltage value PBV during the second period t2 as shown in FIG. 5A.However, if there are cracks on the array substrate LS, the data linesD1 to Dm or the outlines OL1 and OL2 may be disconnected or wireresistance of the data lines D1 to Dm or the outlines OL1 and OL2 mayincrease.

For example, when there are one or more cracks on the array substrate LSand the data lines D1 to Dm or the outlines OL1 and OL2 aredisconnected, the peak black gray level voltage value PBV may not besupplied during the second period t2. Therefore, the voltage value to besupplied to the pixel may decrease to the peak white gray level voltagevalue PWV during the first period t1, and the peak white gray levelvoltage value PWV may be maintained during the second period t2, asshown in FIG. 5B. Since the pixels coupled to the disconnected data lineor outline due to cracks may express peak white gray level, a brightline may show.

In addition, when there are one or more cracks on the array substrate LSand wire resistance of the data lines D1 to Dm or the outlines OL1 andOL2 increase, even if the peak black gray level voltage value PBV issupplied during the second period t2, the voltage value to be suppliedto the pixel will not decrease to the peak white gray level voltagevalue PWV during the first period t1 and increase to the peak black graylevel voltage value PBV during the second period t2 as shown in FIG. 5C.As a result, the pixels coupled to the data line or outline where wireresistance increased due to cracks will express gray gradation, andtherefore a less bright line may show.

As discussed above, according to one embodiment, the initializationsignal IV may be supplied via the initialization transistors IT1, IT2,and IT3 during the first period t1 of every horizontal period. The testsignal TV may be supplied through the first test transistors TT1 duringthe second period t2. Therefore, based on disconnection or change inwire resistance of the data lines D1 to Dm, or disconnection or changein wire resistance of the outline outside the display area DA, adetermination may be made as to whether cracks exist on the arraysubstrate LS. For example, when a bright line or a less bright lineshows, it may be determined that cracks are on the array substrate LS.

FIG. 6 illustrates an embodiment of a coupling structure between thetest transistor and the outline and the test transistor and theresistance in FIG. 3. FIG. 7A is a cross-sectional view along line I-I′in FIG. 6. FIG. 7B is a cross-sectional view along line II-II′ in FIG.6. The coupling structure of the first test transistor TT1 coupled tothe first data line D1 and the first outline OL1 and the couplingstructure of the first test transistors TT1 coupled to the second andthird data lines and the resistance R are described below in referenceto FIGS. 6, 7A, and 7B. For purposes of convenience, FIG. 6 shows onlythe first to third data lines D1, D2, and D3 and the first testtransistors TT1 coupled to the first to third data lines D1, D2, and D3.

In FIG. 6, the first transistor TT1 coupled to the first outline OL1 isdefined as a (1-1)-th test transistor TT1-1, and the first testtransistor TT1 coupled to the resistance R as a 1-2 test transistorTT1-2.

Referring to FIGS. 6 and 7A, a control electrode TT_G of the (1-1)-thtest transistor TT1-1 overlaps an active layer TT_ACT in a presetregion. One end of the active layer TT_ACT of the (1-1)-th testtransistor TT1-1 may be coupled to the first data line D1 through afirst contact hole CNT1, and the other end of the active layer TT_ACTmay be coupled to one end of the first outline OL1 through a secondcontact hole CNT2. The first outline OL1 may be adjacent and go at leastpartially around the display area DA once as shown in FIG. 3. The otherend of the first outline OL1 may be coupled to a bridge electrode BE viaa third contact hole CNT3. The bridge electrode BE may be coupled to atest voltage line TVL through a fourth contact hole CNT4. The testvoltage line TVL may be a line coupled to any one of the test pads TVP1and TVP2 to which the test signal TV is supplied.

The control electrode TT_G of the (1-1)-th test transistor TT1-1 and thebridge electrode BE may include a first metal pattern. The active layerTT_ACT of the (1-1)-th test transistor TT1-1 may include a semiconductorpattern. The first data line D1, the first outline OL1, and the testvoltage line TVL may include a second metal pattern. The first metalpattern may be a gate metal pattern, and the second metal pattern may bea source/drain metal pattern. The semiconductor pattern may include, forexample, polysilicon, single crystal silicon, amorphous silicon, or anoxide semiconductor material. A gate insulator GI may be between thefirst metal pattern and the semiconductor pattern to insulate the firstmetal pattern and the semiconductor pattern. Also, in order to insulatethe semiconductor pattern and the second metal pattern, a passivationlayer PAS may be between the semiconductor pattern and the second metalpattern.

Referring to FIGS. 6 and 7B, the control electrode TT_G of the (1-2)-thtest transistor TT1-2 may overlap the active layer TT_ACT in a presetregion. One end of the active layer TT_ACT of the (1-2)-th testtransistor TT1-2 may be coupled to the second or third data line D2 orD3 via the first contact hole CNT1, and the other end of the activelayer TT_ACT may be coupled to the bridge electrode through a fifthcontact hole CNT5. The bridge electrode BE may be coupled to the testvoltage line TVL via a fourth contact hole CNT4.

The control electrode TT_G of the (1-2)-th test transistor TT1-2 and thebridge electrode BE may include the first metal pattern. The activelayer TT_ACT of the (1-2)-th test transistor TT1-2 may the semiconductorpattern. The second and third data lines D2 and D3 and the test voltageline TVL may include the second metal pattern. The first metal patternmay be a gate metal pattern, and the second metal pattern may be thesource/drain metal pattern. The semiconductor pattern may include, forexample, polysilicon, single crystal silicon, amorphous silicon, or anoxide semiconductor material. The gate insulator GI may be between thefirst metal pattern and the semiconductor pattern to insulate the firstmetal pattern and the semiconductor pattern. Also, in order to insulatethe semiconductor pattern and the second metal pattern, a passivationlayer PAS may be between the semiconductor pattern and the second metalpattern.

The active layer TT_ACT of the 1-2 test transistor TT1-2 may be longerthan the active layer TT_ACT of the (1-1)-th test transistor TT1-1. Forexample, the active layer TT_ACT of the 1-2 test transistor TT1-2 may belonger than the active layer TT_ACT of the (1-1)-th test transistorTT1-1 and may act as the resistance R. For example, the active layerTT_ACT of the (1-1)-th test transistor TT1-1 into which impurities aredoped may function as the resistance R. By designing the resistancevalue of the resistance R as substantially the same as the wireresistance value of the first outline OL1, the voltage value differencein test signal due to wire resistance of the first outline OL1 may beminimized.

FIG. 8 illustrates another embodiment of an array substrate of displaypanel 10. Referring to FIG. 8, the display panel 10 includes the arraysubstrate LS and the opposite substrate. The array substrate LS isdivided into the display area DA which includes pixels P for displaysimages, and a non-display area NDA outside the display area DA.

The pixels P are in the display area DA of the array substrate LS. Thedata pads DP1 to DPo, the initialization control pads IP1, IP2, and IP3,the first test control pad TP1, the test pads TVP1 and TVP2, theinitialization transistors IT1, IT2, and IT3, the first test transistorsTT1, the resistances R, and the outlines OL1 and OL2 are in thenon-display area DA of the array substrate LS.

The pixels P of the array substrate LS, the data pads DP1 to DPo, theinitialization control pads IP1, IP2, and IP3, the first test controlpad TP1, the test pads TVP1 and TVP2, the initialization transistorsIT1, IT2, and IT3, the first test transistors TT1, the resistances R,and the outlines OL1 and OL2 of the display panel 10 in FIG. 8 may besubstantially the same as in FIG. 3.

The outlines OL1 and OL2 of the array substrate LS of the display panel10 are coupled to the data lines D2 and Dm coupled to the green pixelsGP through the first test transistors TT1. For example, the first testtransistor TT1 coupled to the outline may be coupled to the data linethat is coupled to the green pixels GP. Since human color perceptioncapability for green color is better than for red or blue color, thecracks in the non-display area NDA may be more easily determined becauseless bright lines are more easily perceived according to the embodimentin FIG. 8.

When the outlines OL1 and OL2 are coupled to the data lines D2 and Dmthat are coupled to the green pixels GP through the first testtransistor TT1, the resistances R may be coupled only to the first testtransistors TT1, which are coupled to the data lines coupled to thegreen pixels GP among the first test transistors TT1 that are notcoupled to the outlines OL1 and OL2. As a result, the embodiment in FIG.8 may reduce more resistances R than the embodiment in FIG. 3. Thus,there may be less circuit complexity in the embodiment of FIG. 8.

FIG. 9 illustrates another embodiment of an array substrate of thedisplay panel 10. Referring to FIG. 9, the display panel 10 includes thearray substrate LS and the opposite substrate. The array substrate LS isdivided into the display area DA including pixels P to display and thenon-display area NDA outside the display area DA. The pixels P are inthe display area DA of the array substrate LS. The pixels P of the arraysubstrate LS of the display panel 10 according to the embodiment in FIG.9 may be substantially the same as the embodiment in FIG. 3

The data pads DP1 to DPm, the initialization control pads IP1, IP2, andIP3, the initialization pads IVP1, IVP2, and IVP3, first test controlpad TP1, the test pads TVP1 and TVP2, the initialization transistorsIT1, IT2, and IT3, the first test transistors TT1, the resistances R,and the outlines OL1 and OL2 are in the non-display area DA of the arraysubstrate LS. Also, when the scan driver 20 is formed using the ASGmethod or the GIP method, the scan driver 20 may be in the non-displayarea NDA outside the display area DA.

The data pads DP1 to DPm may be coupled to the data lines D1 to Dm. Wheninspecting cracks of the array substrate LS, no signal or power may besupplied to the data pads DP1 to DPm. The source drive IC 30 may beattached to the completed display panel 10 as shown in FIG. 1. The datapads DP1 to DPm may be coupled to the source drive IC 30. For example,since the source drive IC 30 supplies data signals to the data pads DP1to DPm, the source drive IC 30 may supply data signals to the data linesD1 to Dm of the completed display panel 10.

The initialization pads IVP1, IVP2, and IVP3 are coupled to the datalines D1 to Dm through the first test transistors TT1. Theinitialization signals are supplied to the initialization pads IVP1,IVP2, and IVP3. Same or different voltage value of the initializationsignals may be supplied to the initialization pads IVP1, IVP2, and IVP3.For example, same voltage value of the initialization signals may besupplied to the first to third initialization pads IVP1, IVP2, and IVP3.Alternatively, the first voltage value of the initialization signal maybe supplied to the first initialization pad IVP1, the second voltagevalue of the initialization signal may be supplied to the secondinitialization pad IVp2, and the third voltage value of theinitialization signal may be supplied to the third initialization padIVP3.

As shown in FIG. 9, the initialization control pads IP1, IP2, and IP3include three (3) initialization control pads, and the initializationtransistors IT1, IT2, and IT3 include three (3) initializationtransistors. The first initialization control pad IP1 is coupled tocontrol electrodes of the first initialization transistors IT1. Thesecond initialization control pad IP2 is coupled to control electrodesof the second initialization transistors IT2. The third initializationcontrol pad IP3 is coupled to control electrodes of the thirdinitialization transistors IT3. The first initialization control signalis supplied to the first initialization control pad IP1, the secondinitialization control signal is supplied to the second initializationcontrol pad IP2, and the third initialization control signal is suppliedto the third initialization control pad IP3.

The first test control pad TP1 is coupled to each control electrode ofthe first test transistors TT1. The test control signal is supplied tothe first test control pad TP1.

The test pads TVP1 and TVP2 are coupled to first electrodes of the firsttest transistors TT1. The test signals are supplied to the test padsTVP1 and TVP2. Same or different test signals are supplied to the firstand second test pads TVP1 and TVP2. For example, same test signals maybe supplied to the first and second test pads TVP1 and TVP2.Alternatively, the first test signal may be supplied to the first testpad TVP1, and the second test signal may be supplied to the second testpad TVP2.

The initialization transistors IT1, IT2, and IT3 may be coupled betweenthe data lines D1 to Dm and the initialization pads IVP1, IVP2, andIVP3. The first initialization transistors It1 may be coupled betweenthe data lines and the first initialization pads IVP1. The secondinitialization transistors IT2 may be coupled between the data lines andthe second initialization pads IVP2. The third initializationtransistors IT3 may be coupled between the data lines and the thirdinitialization pads IVP3. The control electrodes of the firstinitialization transistors IT1 may be coupled to the firstinitialization control pad IP1. The control electrodes of the secondinitialization transistors IT2 may be coupled to the firstinitialization control pad IP2. The control electrodes of the thirdinitialization transistors IT3 may be coupled to the thirdinitialization control pad IP3.

For example, each control electrode of the first initializationtransistors IT1 may be coupled to the first initialization control padIP1, the first electrode may be coupled to any one of the data lines D1to Dm, and the second electrode may be coupled to the firstinitialization control pads IVP1. Each control electrode of the secondinitialization transistors IT2 may be coupled to the secondinitialization control pad IP2, the first electrode may be coupled toany one of the data lines D1 to Dm, and the second electrode may becoupled to the second initialization control pads IVP2. ach controlelectrode of the third initialization transistors IT3 may be coupled tothe third initialization control pad IP3, the first electrode may becoupled to any one of the data lines D1 to Dm, and the second electrodemay be coupled to the third initialization control pads IVP3.

Adjacent first and second initialization transistors IT1 and IT2 may becoupled to one data line. The third initialization transistor IT3adjacent to the first and second initialization transistors IT1 and IT2may be coupled to a different data line. For example, the first andsecond initialization transistors IT1 and IT2, which are adjacent toeach other, may be coupled to the first data line D1. The thirdinitialization transistor IT3, which is adjacent to the first and secondinitialization transistors IT1 and IT2, may be coupled to the seconddata line D2 as shown in FIG. 9.

The first test transistors TT1 may be coupled between the data lines D1to Dm and the test pads TVP1 and TVP2. The control electrodes of thefirst test transistors TT1 may be coupled to the first test control padTP1. For example, each control electrode of the first test transistorsTT1 may be coupled to the first test control pad TP1, the firstelectrode may be coupled to any one of the test pads TVP1 and TVP2, andthe second electrode may be coupled to any one of the data lines D1 toDm.

The outline may be between the first electrode of the first testtransistor TT1 and the test pad. For example, as shown in FIG. 3, thefirst outline OL1 may be between the first electrode of the first testtransistor TT1 coupled to the first data line D1 and the first test padTVP1. A second outline OL2 may be between the first electrode of thefirst test transistor TT1 coupled to the m-th data line Dm and thesecond test pad TVP2. For example, the first outline OL1 may be coupledbetween the first electrode of the first test transistor TT1, that iscoupled to the first data line D1 and the first test pad TVP1. Thesecond outline OL2 may be coupled between the first electrode of thefirst test transistor TT1, that is coupled to the m-th data line Dm andthe second test pad TVP2.

Each of the outlines OL1 and OL2 may be outside the display area DA. Forexample, the first outline OL1 may be outside of the left side andoutside the upper side of the display area DA. The second outline OL2may be outside the right side and outside of the upper side of thedisplay area DA. Also, when the scan driver 20 is in the non-displayarea NDA outside of one side of the display area DA, the outlines OL1and OL2 may be further outside than the scan driver 20. Also, theoutlines OL1 and OL2 may be on the outermost side, among the structuresat the array substrate LS, to surround the structures at the arraysubstrate LS. The structures at the array substrate LS may refer to anystructure other than the pads.

For example, each of the outlines OL1 and OL2 may be adjacent to and atleast partially go around the display area DA once. In one embodiment,the first outline OL1 may be adjacent to and go around the left side andupper side of the display area DA once, and the second outline OL2 maybe adjacent to and go around the outside of the right side and upperside of the display area DA once.

A voltage value difference may exist between the test signal supplied tothe first test transistors TT1 via the outlines OL1 and OL2 (from thetest pads TVP1 and TVP2) and the test signal supplied to the first testtransistors TT1 without passing through the outlines OL1 and OL2 (fromthe test pads TVP1 and TVP2). This voltage value differencevoltage valuedifference may occur because of a difference in wire resistances betweenthe outlines OL1 and OL2.

To prevent the voltage value difference from occurring, resistances Rmay be placed between the first electrodes of the first test transistorsTT1 (which are not coupled to the outlines OL1 and OL2) and the testpads TVP1 and TVP2. As a result, any voltage value difference in testsignal attributable to wire resistances of the outlines OL1 and OL2 maybe reduced or minimized. For example, a resistance value of the firstoutline OL1, a resistance value of the second outline OL2, and aresistance value of the resistance R may be set to be substantially thesame in order to reduce or minimize the voltage value difference in testsignal due to wire resistances of the outlines OL1 and OL2. An exampleof the resistances R is explained above with reference to FIGS. 6, 7Aand 7B.

According to one embodiment, in the array substrate LS of the displaypanel, the initialization transistors IT1, IT2, and IT3 are in the uppernon-display area NDA. Also, in this embodiment, the data pads DP1 toDPm, the initialization control pads IP1, IP2, and IP3, the first testcontrol pad TP1, the initialization pads IVP1, IVP2, and IVP3, the testpads TVP1 and TVP2, the first test transistors TT1 and the resistances Rare in the lower non-display area NDA. The arrangement of the data padsDP1 to DPm, the initialization control pads IP1, IP2 and IP3, the firsttest control pad TP1, the initialization pads IVP1, IVP2, and IVP3 andthe test pads TVP1 and TVP2 may be different in another embodiment.

As discussed above, in the embodiment of FIG. 3, the initializationtransistors that initialize the data lines D1 to Dm are coupled to thedata pads DP1 to DPm, while in the embodiment of FIG. 9 theinitialization transistors that initialize the data lines D1 to Dm arecoupled to the initialization pads IVP1, IVP2, and IVP3. Also, in theembodiment of FIG. 3, the first test transistors TT1 and the resistancesR are in the upper non-display area NDA and the initializationtransistors IT1, IT2, and IT3 are in the lower non-display area NDA,while in the embodiment of FIG. 9 the initialization transistors IT1,IT2, and IT3 are in the upper non-display area NDA and the first testtransistors TT1 and the resistances R are in the lower non-display areaNDA.

The signals supplied to the display panel in the embodiment of FIG. 9may be substantially the same as FIG. 4. For example, the initializationcontrol signals IS1, IS2, and IS3 supplied to the initialization controlpads IP1, IP2, and IP3, the test control signal TS supplied to the firsttest control pad TP1, the initialization signal IV supplied to theinitialization pads IVP1, IVP2, and IVP3, the test signal TV supplied tothe test pads TVP1 and TVP2, and the scan signals SCAN1, SCAN2, SCAN3,and SCANn supplied to the scan lines S1 to Sn may be substantially thesame as FIG. 4. The signals supplied to the display panel in theembodiment of FIG. 9 may be different from those in FIG. 4 in anotherembodiment. Also, the method for inspecting cracks of the display panelaccording to the embodiment of FIG. 9 may be substantially the same asin FIGS. 3 and 4, but this also is not a necessity.

FIG. 10 illustrates another embodiment of the array substrate of thedisplay panel 10. Referring to FIG. 10, the display panel 10 includesthe array substrate LS and the opposite substrate. The array substrateLS is divided into the display area DA including pixels P for displayingimages and non-display area NDA outside the display area DA.

The pixels P are in the display area DA of the array substrate LS. Thedata pads DP1 to DPm, the initialization control pads IP1, IP2, and IP3,the initialization pads IVP1, IVP2, and IVP3, test control pads TP1-1,TP1-2, TP2-1, and TP2-2, the test pads TVP1 and TVP2, the initializationtransistors IT1, IT2, and IT3, the test transistors TT1 and TT2, theresistances R and the outlines OL1 and OL2 are in the non-display areaDA of the array substrate LS. The pixels P, the data pads DP1 to DPm,the initialization control pads IP1, IP2, and IP3, the initializationpads IVP1, IVP2, and IVP3, the test pads TVP1 and TVP2, and theinitialization transistors IT1, IT2, and IT3 of the array substrate LSof the display panel 10 in FIG. 10 may be substantially the same as theembodiment in FIG. 9, but this is not a necessity.

The first test control pads TP1-1 and TP1-2 are coupled to controlelectrodes of the first test transistors TT1. The (1-1)-th test controlpads TP1-1 are coupled to a control electrode of the first testtransistor TT1 coupled to the first data line D1 and a control electrodeof the first test transistor TT1 coupled to the m-th data line Dm. The(1-2)-th test control pad TP1-2 is coupled to control electrodes of thefirst test transistor TT1 coupled to the remaining data lines D2 toDm−1. The first test control signal may be supplied to the first testcontrol pads TP1-1 and TP1-2.

The embodiment of FIG. 10 further includes second test transistors TT2and second test control pads TP2-1 and TP2-2. The second test controlpads TP2-1 and TP2-2 are coupled to control electrodes of the secondtest transistors TT2. The (2-1)-th test control pad TP2-1 are coupled toa control electrode of a second test transistor TT2 coupled to the firstdata line D1. The (2-2)-th test control pad TP2-2 is coupled to acontrol electrode of the second test transistor TT2 coupled to the m-thdata line Dm. The second test control signal is supplied to the secondtest control pads TP2-1 and TP2-2.

The first test transistors TT1 are coupled between the data lines D1 toDm and the test pads TVP1 and TVP2. The control electrodes of the firsttest transistors TT1 are coupled to the first test control pads TP1-1and TP1-2. For example, each control electrode of the first testtransistors TT1 is coupled to one of the first test control pads TP1-1or TP1-2, the first electrode is coupled to one of the test pads TVP1 orTVP2, and the second electrode is coupled to one of the data lines D1 toDm.

The second test transistors TT2 are coupled between the data lines D1 toDm and the outlines OL1 and OL2. The control electrodes of the secondtest transistors TT2 are coupled to the second test control pads TP2-1and TP2-2. For example, each control electrode of the second testtransistors TT2 is coupled to one of the second test control pads TP2-1or TP2-2, the first electrode is coupled to one of the outlines OL1 orOL2, and the second electrode is coupled to one of the data lines D1 toDm.

The outlines OL1 and OL2 are coupled between the second test transistorsTT2 and the test pads TVP1 and TVP2. The first outline OL1 is coupledbetween the first electrode of the second test transistor TT2 coupled tothe first data line D1 and the first test pad TVP1. The second outlineOL2 is coupled between the first electrode of the second test transistorTT2 coupled to the m-th data line Dm and the second test pad TVP2.

Each of the outlines OL1 and OL2 may be outside of the display area DA.For example, the first outline OL1 may be adjacent to and outside theleft side and upper side of the display area DA. The second outline OL2may be outside the right side and upper side of the display area DA.Also, when the scan driver 20 is in the non-display area NDA adjacentone side of the display area DA, the outlines OL1 and OL2 may be furtheroutside than the scan driver 20. Also, the outlines OL1 and OL2 may beon the outermost side to surround the structures at the array substrateLS. These structures may refer to any structure other than the pads.

A voltage value difference may exist between the test signal supplied tothe second test transistors TT2 via the outlines OL1 and OL2 (from thetest pads TVP1 and TVP2) and the test signal supplied to the first testtransistors TT1 without passing through the outlines OL1 and OL2 (fromthe test pads TVP1 and TVP2). The voltage value difference may occur asa result of differences in wire resistances of the outlines OL1 and OL2.

To prevent the voltage value difference from occurring, resistances Rmay be placed between the first electrodes of the first test transistorsTT1 not coupled to the outlines OL1 and OL2 and the test pads TVP1 andTVP2. As a result, the voltage value difference in test signal due todifferences of resistance values in wire resistances of the outlines OL1and OL2 may be reduced or minimized. For example, the resistance valueof the first outline OL1, the resistance value of the second outlineOL2, and the resistance value of the resistance R may be substantiallythe same in order to reduce or minimize the difference in test signalsdue to wire resistances of the outlines OL1 and OL2. An example of theresistances R is explained above with reference to FIGS. 6, 7A, and 7B.

In the embodiment of FIG. 10, in the array substrate LS of the displaypanel, the initialization transistors IT1, IT2, and IT3 and the secondtest transistors TT2 are in the upper non-display area NDA and the datapads DP1 to DPm, the initialization control pads IP1, IP2, and IP3, thetest control pads TP1-1, TP1-2, TP2-1, and TP2-2, the initializationpads IVP1, IVP2, and IVP3, the test pads TVP1 and TVP2, the first testtransistors TT1, and the resistances R are in the lower non-display areaNDA. The arrangement of the data pads DP1 to DPm, the initializationcontrol pads IP1, IP2, and IP3, the first test control pad TP1, theinitialization pads IVP1, IVP2, and IVP3, and the test pads TVP1 andTVP2 may be different in another embodiment.

The signals supplied to the display panel in the embodiment of FIG. 10may be substantially the same as FIG. 4. For example, the initializationcontrol signals IS1, IS2, and IS3 supplied to the initialization controlpads IP1, IP2, and IP3, the test control signal TS supplied to the testcontrol pads TP1-1, TP1-2, TP2-1, and TP2-2, the initialization signalIV supplied to the initialization pads IVP1, IVP2, and IVP3, the testsignal TV supplied to the test pads TVP1 and TVP2, and the scan signalsSCAN1, SCAN2, SCAN3, and SCANn supplied to the scan lines S1 to Sn maybe substantially the same as FIG. 4, but this is not a necessity. Also,the method for inspecting cracks of the display panel corresponding tothe embodiment of FIG. 10 may be substantially the same as in FIGS. 3and 4, but this is not a necessity.

FIG. 11 illustrating an embodiment of a method for manufacturing adisplay device. The method includes manufacturing the array substrate LSof the display panel 10 (S101). The array substrate LS of the displaypanel 10 may be manufactured, for example, according to the embodimentsof FIG. 3, 8, 9, or 10.

Next, an inspection is performed to determine whether there are crackson the array substrate LS of the display panel 10 (S102). Inspection ofthe cracks on the array substrate LS may be performed, for example,according to the method described with reference to FIGS. 3 and 4. Whencracks are determined to exist on the array substrate LS of the displaypanel 10, the array substrate LS may be determined as defective (S103).

When no cracks are determined to exist on the array substrate LS of thedisplay panel 10, the array substrate LS may be determined as havingfair quality and a module process may be performed (S104). For example,if the array substrate LS is determined as having fair quality, theopposite substrate may be attached to the array substrate LS of thedisplay panel 10, the flexible film to which the source drive IC ismounted may be attached to the array substrate, the flexible film may beattached to the source printed circuit board, and the control printedcircuit board to which the timing controller is mounted and the sourceprinted circuit board may be coupled using the flexible cable.

In this embodiment, inspection may be performed to determine whethercracks have occurred on the array substrate LS before performing themodule process. When the array substrate LS is determined to havecracks, the array substrate LS is identified as defective. As a result,a waste of manufacturing costs is prevent by not performing a moduleprocess for a defective display panel.

FIG. 12 illustrates another embodiment of a method for manufacturing adisplay device. In this embodiment, operations S201 to 5204 may besubstantially the same as operations S101 to S104 in FIG. 11.

Additionally, an operation 205 may be included in which re-inspection isperformed to determine whether there are cracks on the array substrateLS of the display panel 10 after the module process is completed. Thisre-inspection operation may be performed because cracks may occur on thearray substrate LS due to impact during the module process. Byperforming this re-inspection operation, the release of defectiveproducts may be reduced or minimized.

The inspection of cracks on the array substrate LS may be performedaccording to the crack inspection method of the display panel as inFIGS. 3 and 4. Additionally, or alternatively, the array substrate LS ofthe display panel 10 may be manufactured according to the embodiment inFIG. 3 or 8.

When the array substrate LS is manufactured according to the embodimentof FIG. 9 or 10, the source drive IC may be coupled to the test controlpads coupled to control electrodes of the first test transistors TT1 dueto module process. Also, the source drive IC may supply the first gateoff voltage value Voff1 to the test control pads. Therefore, it may bedifficult to inspect whether cracks have occurred on the array substrateLS of the display panel 10 after module process is completed.

Thus, according to the present embodiment, re-inspection may beperformed to determine whether cracks have occurred on the arraysubstrate LS after module process is performed The display panel 10 maybe determined to be defective if cracks are determined to have occurred.As a result, the release of a display panel with cracks on the arraysubstrate LS (e.g., which occurred both before and during moduleprocess) may be prevented.

By way of summation and review, according to one embodiment,initialization signals may be supplied via initialization transistorsduring a first period, and test signals may be supplied through thefirst test transistors during a second period. As a result, adetermination may be made as to whether cracks have occurred in thedisplay area of the array substrate, for example, based on disconnectionor change in wire resistances of the data lines.

According to this or another embodiment, outlines may be in anon-display area (outside a display area) of the array substrate. As aresult, a determination may be made as to whether cracks have occurredin the non-display area of the array substrate, for example, based ondisconnection or a change in wire resistances of the outline caused bythe cracks.

According to this or another embodiment, resistances may be placedbetween the first test transistors (not coupled to the outlines) and thetest pads to which test signals are supplied. As a result, a voltagevalue difference in the test signals due to differences in wireresistances of the outlines may be reduced or minimized.

According to this or another embodiment, the outlines may be coupled tothe data lines, that are coupled to the predetermined color (e.g.,green) of pixels or sub-pixels through the test transistors. Becausehuman perception capability for green color is superior to red or bluecolor, it may be easier to determine whether cracks have occurred at thenon-display area. Thus, the resistances may only be placed at the testtransistors coupled to the data lines coupled to the green pixels, orsub-pixels, among the test transistors not coupled to the outlines. As aresult, the resistances may be reduced, and circuit complexity may bereduced. In another embodiment, the resistances may be placed for allcolor pixels or sub-pixels or a subset of the color pixels or sub-pixelsincluding or excluding green.

According to this or another embodiment, a determination may be made asto whether cracks have occurred on the array substrate before a moduleprocess is performed. An array substrate with cracks may be determinedas defective. As a result, a module process may not be performed fordefective display panels and, thus, manufacturing costs may not bewasted.

According to this or another embodiment, a re-inspection operation maybe performed to determine whether cracks have occurred on the arraysubstrate after a module process is performed. Display panels withcracks may be determined as defective. As a result, the release ofdisplay panels with cracks that have occurred on the array substrateduring the module process may be prevented.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of skill in the art as of thefiling of the present application, features, characteristics, and/orelements described in connection with a particular embodiment may beused singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwiseindicated. Accordingly, it will be understood by those of skill in theart that various changes in form and details may be made withoutdeparting from the spirit and scope of the present invention as setforth in the following claims.

What is claimed is:
 1. A display device, comprising: a display areaincluding pixels coupled to data lines and scan lines; a test pad toreceive a test signal; a plurality of first test transistors coupledbetween the data lines of the display area and the test pad; and atleast one outline coupled between one of the first test transistors andthe test pad, the at least one outline in a non-display area outside thedisplay area.
 2. The display device as claimed in claim 1, wherein theat least one outline traverses a path that is adjacent the display areaonce.
 3. The display device as claimed in claim 1, wherein: the firsttest transistor is coupled to the at least one outline, the at least oneoutline is coupled to a data line, and the data line is coupled to atleast one green pixel or sub-pixel in the display area.
 4. The displaydevice as claimed in claim 1, further comprising: a resistance betweenone of the first test transistors that is not coupled to the at leastone outline and the test pad.
 5. The display device as claimed in claim1, further comprising: a test control pad coupled to control electrodesof the first test transistors; a plurality of initialization transistorscoupled between the data lines of the display area and pads to receiveinitialization signals; and a plurality of initialization control padscoupled to control electrodes of the initialization transistors.
 6. Thedisplay device as claimed in claim 5, further comprising: a plurality ofdata pads coupled to the data lines.
 7. The display device as claimed inclaim 6, wherein the test pad, the test control pad, the initializationcontrol pads, the data pads, the test transistors, the initializationtransistors, and the at least one outline are in the non-display area.8. The display device as claimed in claim 5, wherein the test controlpad is to receive a test control signal that is opposite to aninitialization control signal received by one of the initializationcontrol pads.
 9. The display device as claimed in claim 8, wherein: scansignals are coupled to the scan lines within a period during which thetest control signal is supplied as first gate-on voltage value, and thescan signals are supplied as second gate-on voltages value.
 10. Thedisplay device as claimed in claim 1, further comprising: a plurality offirst test control pads coupled to control electrodes of the first testtransistors; a plurality of initialization transistors coupled betweenthe data lines in the display area and initialization pads to receiveinitialization signals; a plurality of initialization control padscoupled to control electrodes of the initialization transistors; asecond test transistor coupled between one of the data lines and the atleast one outline; a second test control pad coupled to a controlelectrode of the second test transistor; and a plurality of data padscoupled to the data lines.
 11. The display device as claimed in claim10, wherein the first and second test control pads are to receive a testcontrol signal opposite to an initialization control signal received byone of the initialization control pads.
 12. The display device asclaimed in claim 11, wherein scan signals coupled to the scan lines aresupplied as second gate-on voltages, during a period when the testcontrol signal is supplied as a first gate-on voltage.
 13. The displaydevice as claimed in claim 10, wherein the test pad, the first andsecond test control pads, the initialization control pads, the datapads, the first and second test transistors, the initializationtransistors, and the at least one outline are in the non-display area.14. A method for manufacturing a display device, the method comprising:manufacturing an array substrate of a display panel; and inspecting thearray substrate of the display panel for a crack.
 15. The method asclaimed in claim 14, wherein the manufacturing includes forming: datalines on the array substrate of the display panel, scan lines crossingthe data lines, a plurality of pixels coupled to the data lines and thescan lines, a test pad, a plurality of first test transistors coupledbetween the data lines of a display area and the test pad, at least oneoutline coupled between one of the first test transistors and the testpad, the at least one outline in a non-display area, a control padcoupled to control electrodes of the first test transistors, a pluralityof initialization transistors coupled between the data lines of thedisplay area and pads to receives initialization signals, and aplurality of initialization control pads coupled to control electrodesof the initialization transistors.
 16. The method as claimed in claim15, wherein the inspecting includes: supplying a test signal to the testpad, supplying a test control signal to the control pad, and supplyinginitialization control signals to the initialization control pads,wherein the test control signal is opposite to one of the initializationcontrol signals.
 17. The method as claimed in claim 14, wherein themanufacturing includes forming: a plurality of data lines on the arraysubstrate of the display panel, a plurality of scan lines crossing thedata lines, a plurality of pixels coupled to the data lines and the scanlines, a test pad, a plurality of first test transistors coupled betweenthe data lines of the display area and the test pad, at least oneoutline coupled between one of the first test transistors and the testpad, the at least one outline in a non-display area, a plurality offirst test control pads coupled to control electrodes of the first testtransistors, a plurality of initialization transistors coupled betweenthe data lines of a display area and the pads to receive initializationsignals, a plurality of initialization control pads coupled to controlelectrodes of the initialization transistors, a second test transistorcoupled between the initialization transistor and the at least oneoutline; and a second test control pad coupled to a control electrode ofthe second test transistor.
 18. The method as claimed in claim 17,wherein the inspecting includes: supplying a test signal to the testcontrol pad, supplying a test control signal to the first and secondtest control pads; an supplying initialization control signals to theinitialization control pads, wherein the test control signal is oppositeto one of the initialization control signals.
 19. The method as claimedin claim 14, further comprising: performing a module process; andre-inspecting cracks on the display panel after the module process,wherein the performing includes: attaching the array substrate to anopposite substrate of the display panel; attaching a flexible film tothe array substrate; attaching the flexible film to the source printedcircuit board; and coupling a control printed circuit board and thesource printed circuit board using a flexible cable.
 20. The displaydevice as claimed in claim 4, wherein the resistance is a resistor.